Apparatus For Reducing Fuel Waxing - Patent 8136511

Document Sample
Apparatus For Reducing Fuel Waxing - Patent 8136511 Powered By Docstoc
Description: FIELDOF THE INVENTION Exemplary embodiments of the present invention are related to a fuel supply system for an internal combustion engine and, more specifically, to an apparatus for preventing blockage of a fuel filter element due to wax crystallization of the fuelat low temperatures.BACKGROUND Fuels for internal combustion engines such as diesel fuel, kerosene, light oil, bio-fuels or a combination thereof may include a wax component that is subject to crystallization ("waxing") at temperatures below approximately -10 degrees Celsius. Suspended wax crystals can be trapped by or adhere to the filter media of a fuel filter resulting in partial or complete blockage of the fuel filter. Such blockage of the fuel filter may result in interruption of fuel flow to the engine resulting in areduction of engine output or stalling of the engine. Attempts to alleviate waxing problems inherent with such fuels have involved the application of heating elements in the fuel system supplying the engine. Such heating elements may include fuel tank or fuel line heaters as well as engine blockheaters or heat exchangers. Recirculation of heated fuel from the fuel injection system to the fuel tank has also been utilized. While these and other methods for avoiding waxing of the fuel have met with some success, the devices utilize significantenergy thereby reducing the efficiency of the engine, are costly and may not operate rapidly enough, especially following a cold engine start because the entire volume of fuel is subject to heating rather than directly addressing the wax crystalssuspended therein. Accordingly, it is desirable to provide an apparatus that is effective to eliminate obstruction of fuel filters caused by fuel wax crystallization and that is efficient and effective across the entire operational temperature range of the engine.SUMMARY OF THE INVENTION In one exemplary embodiment of the present invention, a fuel filter assembly for filtering fuel for an internal combustio